System and method for analyzing carbon build up in an engine

• US 9,279,406 B2
• Filed: 03/15/2013
• Issued: 03/08/2016
• Est. Priority Date: 06/22/2012
• Status: Active Grant

• Current Assignee: Illinois Tool Works Inc.
• Original Assignee: Illinois Tool Works Inc.
• Inventors: Thompson, Bernie C., Pederson, Neal R.
• Primary Examiner(s): Low, Lindsay
• Assistant Examiner(s): Jin, George
• Application Number:
  US13/837,581
• Publication Number:
  US 20140182548A1
• Time in Patent Office: 1,089 Days
• Field of Search: 731/143.1, 731/140.6, 731/143.3, 731/16, 731/15, 731/146.9, 731/147.6, 123/406.19, 701/29.1, 701/101, 701/111, 701/102, 701/30.5
• US Class Current: 1/1
• CPC Class Codes: F02P 17/02 Checking or adjusting ignition timing
• CPC Class Codes: F02P 5/04 automatically, as a function of the working conditions of the engine or vehicle or of the atmospheric conditions dependent on position of personal controls of engine F02P5/02
• CPC Class Codes: G01M 15/04 Testing internal-combustion engines
• CPC Class Codes: G01M 15/10 by monitoring exhaust gases or combustion flame
• CPC Class Codes: G01M 15/106 using pressure sensors
• CPC Class Codes: G01M 15/11 by detecting misfire
• CPC Class Codes: G07C 5/006 Indicating maintenance
• CPC Class Codes: G07C 5/0808 Diagnosing performance data testing of vehicles G01M17/00; testing of electrical installation on vehicles G01R31/005

Abstract

An induction cleaning analyzing system includes a pressure sensor, an ignition event detector, and a control module. The pressure sensor measures airflow pressures of intake air and/or exhaust from cylinders in a common airflow pathway of a vehicle. The ignition event detector determines ignition events of the cylinders. The control module obtains pressure waveforms representative of the airflow pressures and divides the pressure waveforms into waveform segments. The control module associates different subsets of the waveform segments with different ones of the cylinders using the ignition events. The control module also identifies cyclic variations in the airflow pressures flowing in the common airflow pathway and caused by at least one of the cylinders by examining the waveform segments associated with the at least one of the cylinders.

Claims

1. A method of identifying cyclic variations in combustion efficiency in cylinders of an internal combustion engine with aid of instrumentation, the engine including an air induction system, the cylinders, means for generating ignition events for the cylinders, and an exhaust system, the instrumentation including one or more microprocessors programmed with one or more software routines, memory, and means for measuring cylinder pressure pulses;

the method including;

running the engine through a number of combustion cycles;

measuring the pressure pulses with the means for measuring cylinder pressure pulses;

generating a waveform from the cylinder pressure pulses that are measured;

dividing the waveform of the cylinder pressure pulses that are measured into waveform cycles and cycle segments, wherein each of the waveform cycles represents a complete combustion cycle of the engine, wherein each of the cycle segments represents a combustion cycle of a separate cylinder of the cylinders in the engine, and wherein a total number of the cycle segments during the complete combustion cycle of the engine equals a total number of the cylinders;

performing an identifier sequence by marking the cycle segments from the complete combustion cycle of the engine with separate and distinct identifiers associated with different cycles of the cylinders, and repeating the identifier sequence for a number of successive complete combustion cycles of the engine;

and comparing each individual cycle segment of the cycle segments during a particular complete combustion cycle of the engine with the cycle segment having a same identifier for the number of the successive complete combustion cycles of the engine to identify cycle-to-cycle variations of the pressure pulses in the cycle segments for each of the cylinders;

determining a carbon buildup in the air induction system of the engine from the cycle-to-cycle pressure variations;

chemically cleaning the air induction system based on carbon buildup from the air induction system;

repeating measuring the pressure pulses, generating the waveform, dividing the waveform into the waveform cycles and the cycle segments, performing the identifier sequence by marking the cycle segments, comparing each individual cycle segment, and determining the carbon buildup in the air induction system from the cycle to cycle variations after cleaning the air induction system.

2. The method as set forth in claim 1, wherein the instrumentation further includes means for detecting at least some of the ignition events, and wherein dividing the waveform into the waveform cycles and the cycle segments includes utilizing the at least some of the ignition events that are detected.

3. The method as set forth in claim 2, wherein the means for detecting at least some of the ignition signals includes an antenna, and further including placing the antenna relative to the engine so that the antenna can detect at least some of the ignition events, and wherein the one or more software routines includes a first routine to determine if whether the antenna is properly positioned relative to the engine such that the antenna is detecting at least some of the ignition events, and further comprising determining if whether the antenna is properly positioned before proceeding to identify the cycle-to-cycle variations.

4. The method as set forth in claim 3, wherein, responsive to the antenna not detecting all of the ignition events of the engine, the one or more software routines includes a second routine to identify and install waveform divisions on the waveform that are not based on the ignition events that are detected by the antenna, and

wherein dividing the waveform into the waveform cycles and the cycle segments includes utilizing the ignition events that are detected by the antenna to install first division marks on the waveform and identify and installing second division marks in locations along the waveform where at least one of the first division marks is missing because at least one of the ignition events was not detected by the antenna.

5. The method as set forth in claim 1, wherein the one or more software routines includes a first routine to determine whether the means for measuring the cylinder pressure pulses is properly positioned and properly functioning so that the means for measuring detects all of the pressure pulses from each of the cylinders, and further comprising utilizing the first routine to determine if the means for measuring the cylinder pressure pulses is detecting all of the pressure pulses.

6. The method as set forth in claim 1, wherein the instrumentation includes means for acquiring vehicle identification number (VIN) data associated with the engine being tested, wherein the one or more software routines includes a third routine for analyzing the VIN data to determine a year, make, and model of the engine being tested, and further comprising acquiring the VIN data for the engine being tested and determining the year, make, and model of the engine.

7. The method as set forth in claim 6, wherein the VIN data is in the form of a barcode, the means for acquiring VIN data is a barcode scanner, and further comprising scanning the VIN barcode associated with the engine.

8. The method as set forth in claim 6, wherein the memory includes a data base of engines for which a correction factor is to be used with at least some of the one or more software routines, and further comprising checking the data base to determine whether a correction needs to be applied to one or more of the cycle-to-cycle variations and, responsive to determining that the correction needs to be applied, applying the correction factor to the one or more cycle-to-cycle variations.

9. The method as set forth in claim 1, wherein the one or more software routines includes one or more routines for converting the cycle-to-cycle variations associated with each of the cycle segments into a first number representing an average turbulence in the air induction system of the engine, wherein the number also represents associated carbon buildup, and further comprising converting the cycle-to-cycle variations into a second number representing an average waveform turbulence in the air induction system of the engine.

10. The method as set forth in claim 9, wherein the instrumentation includes a carbon buildup scale, wherein the one or more software routines includes a fourth routine for converting the average waveform turbulence to a scale, and further comprising using the number representative of the average waveform turbulence and the fourth routine for converting the average waveform turbulence in the air induction system of the engine to the scale on the carbon build-up scale.

11. The method as set forth in claim 10, wherein the instrumentation includes a screen on which the carbon buildup scale is displayed, and further comprising displaying a scaled carbon buildup on the carbon buildup scale.

12. The method as set forth in claim 11, wherein displaying the scaled carbon buildup on the carbon buildup scale also includes displaying alert indicators selected from a group including one alert that advises that the air induction system should be cleaned and another alert that advises that the air induction system does not have to be cleaned.

13. The method as set forth in claim 9, wherein the one or more software routines includes a plurality of routines for converting the cycle-to-cycle variations associated with each of the cycle segments into average waveform turbulences in the air induction system of the engine, and further including selecting a greatest one of the average waveform turbulences as representative of the average waveform turbulence in the air induction system of such engine and the carbon buildup in the air induction system.

14. The method as set forth in claim 1, further including analyzing the cycle segments for the cycle-to-cycle variations that indicate an engine misfire.

15. The method as set forth in claim 14, further including displaying a visual indicator that the engine being tested has the engine misfire.

16. The method as set forth in claim 1, further comprising inserting the means for measuring the cylinder pressure pulses into the exhaust system, wherein the waveform is an exhaust pressure waveform.

17. The method as set forth in claim 16, wherein the means for measuring the pressure pulses is a venturi, and further comprising inserting the venturi into the exhaust system and measuring the cylinder pressure pulses from the venturi.